Crohn’s disease (CD) is an idiopathic inflammatory bowel disease of the gastrointestinal tract. It is more common in the developed and industrialized countries, particularly in the Western Europe and North America. Up to 20–30% of patients present first symptoms during childhood or adolescence. Traditionally it is diagnosed by clinical indicates, endoscopy and histological findings. Assessment of the disease activity and location along the gastrointestinal tract are of crucial importance for diagnosis and implementation of the proper treatment.